Dear Colleagues,
We are excited to announce the first keynote speakers for the third annual Missouri S&T workshop on “Resilient Supply of Critical Minerals”, funded by the National Science Foundation (NSF).
The workshop will be held in-person (online option available) on the Missouri S&T campus in Rolla, Missouri from August 9-10, 2023, starting at 9:00 AM U.S. Central Time.
Topical sessions will follow the most pressing research needs that were identified during the first workshops. The findings reports from the 2021https://criticalminerals.mst.edu/wp-content/uploads/sites/7/2021/10/Findings-Report_Workshop-on-Resilient-Supply-of-Critical-Minerals_Locmelis-et-al.-2021.pdf and 2022https://criticalminerals.mst.edu/wp-content/uploads/sites/7/2023/02/Summary-Report_2nd-Annual-Workshop-on-Resilient-Supply-of-Critical-Minerals-2022.pdf workshops are available on our workshop website.
[cid:image001.jpg@01D9697C.2F850C10]
The topical sessions are:

1. The Critical Mineral Potential of the USA: Evaluation of existing and exploration for new resources.
2. Mineral Processing & Recycling: Maximizing critical mineral recovery from existing production streams.
3. Critical Mineral Policies: Toward effective and responsible governance.
4. Resource Sustainability: Ethical and environmentally sustainable supply of critical minerals.

Keynote Speakers

Jeffrey Mauk (USGS)

“Uncertainties in translating U.S. critical mineral resources to domestic supply”

●●●●●●●●●●●●●●●●●●●●●●●●●●

Adam C. Simon (University of Michigan)

“The Transition to Renewable Energy: Truths and Consequences”

●●●●●●●●●●●●●●●●●●●●●●●●●●

Isabel Barton (University of Arizona)

“Developing the critical minerals workforce: roadblocks and opportunities”

●●●●●●●●●●●●●●●●●●●●●●●●●●

Roderick G. Eggert (Colorado School of Mines)

“Key considerations in thinking about public policy toward critical minerals”

For updates to the schedule and registration, please refer to the workshop websitehttps://criticalminerals.mst.edu/
Join our mailing listhttps://mst.qualtrics.com/jfe/form/SV_5ja064X4F3Sp7LM to receive updates for the upcoming workshop!

Kind regards,
Marek Locmelis
Workshop Chair
Missouri University of Science & Technology
Geosciences and Geological and Petroleum Engineering
334 McNutt Hall, 1400 North Bishop Avenue
Rolla, Missouri, 65409-0410, USA

Dear Colleagues,
Registration is now open for the third annual Missouri S&T workshop on "Resilient Supply of Critical Minerals", funded by the National Science Foundation (NSF): https://criticalminerals.mst.edu/registration/
We are also accepting applications for travel grants for up to $1000 per person. Instructions can be found on the workshop website:  https://criticalminerals.mst.edu/
The workshop will be held in-person (online option available) on the Missouri S&T campus in Rolla, Missouri from August 9-10, 2023, starting at 9:00 AM U.S. Central Time.
The list of confirmed speakers can be found here:  https://criticalminerals.mst.edu/speakers/
Topical sessions will follow the most pressing research needs that were identified during the first workshops. The findings reports from the 2021https://criticalminerals.mst.edu/wp-content/uploads/sites/7/2021/10/Findings-Report_Workshop-on-Resilient-Supply-of-Critical-Minerals_Locmelis-et-al.-2021.pdf and 2022https://criticalminerals.mst.edu/wp-content/uploads/sites/7/2023/02/Summary-Report_2nd-Annual-Workshop-on-Resilient-Supply-of-Critical-Minerals-2022.pdf workshops are available on our workshop website.
[cid:image001.jpg@01D97C0D.581599D0]
The topical sessions are:

1. The Critical Mineral Potential of the USA: Evaluation of existing and exploration for new resources.
2. Mineral Processing & Recycling: Maximizing critical mineral recovery from existing production streams.
3. Critical Mineral Policies: Toward effective and responsible governance.
4. Resource Sustainability: Ethical and environmentally sustainable supply of critical minerals.

For updates to the schedule and registration, please refer to the workshop websitehttps://criticalminerals.mst.edu/
Kind regards,
Marek Locmelis
Workshop Chair
Missouri University of Science & Technology
Geosciences and Geological and Petroleum Engineering
334 McNutt Hall, 1400 North Bishop Avenue
Rolla, Missouri, 65409-0410, USA

Dear American Mineralogist Readers,

Below are the Paper Highlights for this month’s issue of the American Mineralogist: International Journal of Earth and Planetary Materials. You may also view the American Mineralogist Paper Highlights list at here (http://www.minsocam.org/MSA/Ammin/AM_NotableArticles.html).

The DOI links below will take you to the abstract on GeoScienceWorld.

If you have “IP” access via your institution’s library, it should reveal the whole paper. Consult your institution’s IT department or friendly librarian.

If you have MSA membership, then authenticate in from the American Mineralogist menu (herehttp://www.msapubs.org/ directly). Once at the portal page, click the right-side American Mineralogist link, enter your user name (e-mail address), and your password (membership number). Then search via your browser’s search tools for the paper you want to read. (On Rachel’s computer, it is control-f but we think that is little different for everyone.)

Note that on GSW you can sign up for a table of contents to be sent you when the issue is live -- this is a feature open to anyone who registers on the site.

Thank you for reading American Mineralogist.
Sincerely,
Hongwu Xu
Don Baker

Eu speciation in apatite at 1 bar: An experimental study of valence-state partitioning by XANES, lattice strain, and Eu/Eu* in basaltic systems

https://doi.org/10.2138/am-2022-8388
Tailby et al. describe three new redox calibrations for apatite in basaltic systems. The first calibration includes a methodology that uses the intensity of a negative Eu anomaly relative to neighboring Sm and Gd. The second measures the intensity of the negative Eu anomaly relative to the lattice strain. The third employs a direct XANES measurement on the Eu L3 XANES spectral features.

The effect of composition on chlorine solubility and behavior in silicate melts

https://doi.org/10.2138/am-2022-8450
Thomas and Wood used a sliding chlorine buffer (a mixture of AgCl/AgI and Ag) to determine the fugacities (and activities) of chlorine in many silicate melts. They show that for a wide range of compositions, from basalt, phonolite, andesite, dacite, and rhyolite that Henry's Law is obeyed for the Cl contents of interest in natural volcanic systems. They quantified the effects of different oxides, CaO, FeO, etc., on Cl solubility and determined conditions of NaCl saturation at high pressure and temperature.

High-temperature phase relations of hydrous aluminosilicates at 22 GPa in the AlOOH-AlSiO3OH system

https://doi.org/10.2138/am-2022-8429
Aluminous hydrous phases are key minerals for understanding the Earth's deep water cycle since they have been found as inclusions in superdeep diamonds. In this study, Takaichi et al. investigated the phase relations of hydrous aluminosilicates under pressure conditions corresponding to Earth's interior. They found the formation of two unknown hydrous aluminosilicates. These results indicate that various hydrous aluminosilicates can widely exist within subducting crustal materials in the mantle transition zone to the lower mantle.

Crystallization of spinel from co-existing silicate and sulfide immiscible liquids: an equilibrium case with post-cumulus reactions

https://doi.org/10.2138/am-2022-8473
Mao et al. find that the Kalatongke deposit is an example of where the same mineral phase from two immiscible liquids exhibits approximately equivalent compositions.They determined that the chalcophile element concentration in Cr-magnetite/magnetite of magmatic Ni-Cu deposits results from element exchange with the coexisting sulfide melt, and that the texture and composition of spinel may serve as an indicator for not only the compositional evolution of silicate/sulfide melts but also the percolation and enrichment history of sulfide liquid.

X-ray absorption spectroscopy study of Mn reference compounds for Mn speciation in terrestrial surface environments

https://doi.org/10.2138/am-2022-8236
Zahoransky et al. analyzed a broad range of inorganic and organic Mn compounds by bulk Mn K-edge X-ray absorption spectroscopy (XAS); they evaluated the accuracy of XAS to quantify Mn oxidation states, and explored spectral similarities between and within different Mn species groups. Their study provides the first comprehensive framework for the analysis and interpretation of bulk Mn XAS spectra of natural samples and, thus, for understanding the role of Mn in environmental processes.

Heterogeneous and retarded phase transformation of ferrihydrite on montmorillonite surface: The important role of surface interactions

https://doi.org/10.2138/am-2022-8520
These novel findings enrich our knowledge of the phase transformation characteristics of ferrihydrite under various environmental conditions and advance the understanding of the importance of mineral surface interactions in stabilizing nanominerals and mineral nanoparticles in nature. The findings by Wei et al. also have important implications for assessing mineral composition and the associated ecological environment in wildfire-affected regions. The occurrence of maghemite as an intermediate during the transformation of ferrihydrite in the heteroaggregates also provides an explanation of the origin of magnetism in soils.

Atomic-scale characterization of the oxidation state of Ti in meteoritic hibonite: Implications for early solar system thermodynamics

https://doi.org/10.2138/am-2022-8311
Calcium-aluminum-rich inclusions (CAIs) in meteorites are the oldest solar system solids. Among the CAI phases, hibonite, nominally CaAl12O19, holds particular interest because it is among the first few phases to form from the solar gas and it can incorporate significant amounts of Ti in both Ti3+ and Ti4+. The relative amounts of these cations can reflect the redox conditions under which the grain formed or last equilibrated. Here Zanetta et al. develop a new method for the quantification of Ti oxidation states using electron energy-loss spectroscopy (EELS) in order to apply it to a hibonite grain sampled in the NWA 5028 CR2 chondrite. The aim is to constrain the conditions under which the hibonite grain formed and demonstrate viability of the EELS technique.

Structural behavior of C2/m tremolite to 40 GPa: A high-pressure single-crystal X-ray diffraction study

https://doi.org/10.2138/am-2022-8278
The metastability/compression behavior of tremolite is studied by Ott et al. up to ~40 GPa. The metastable persistence of C2/m tremolite implies that chemically bound water may be carried much deeper than 90 km in steeply subducting cold slabs. This broad metastability range and an increasingly isotropic high-P compressibility contrasts with other clinoamphibole observations, implying that the size of cations interconnecting the I-beams of the clinoamphibole structure exerts a strong control on metastability.

Optimizing Raman spectral collection for quartz and zircon crystals for elastic thermobarometry

https://doi.org/10.2138/am-2022-8423
This study systematically assesses the reproducibility of Raman spectra collected on quartz and zircon crystals and quantifies uncertainties in calculations of entrapment pressures and temperatures as determined using elastic thermobarometry. Three key new contributions include identifying different types of peak drift that operate on different time scales, assessing the reproducibility of different methods for calculating entrapment pressures, and proposing a new method for monitoring peak drift using an external light source. Some methods are resistant to peak drift errors (propagated errors much less than ~1 kbar), while others are highly sensitive (up to several kbar). Ultimately, comprehensive recommendations are provided for analysis that should improve intralaboratory reproducibility and interlaboratory comparisons.

Measuring H2O concentrations in olivine by secondary ionization mass spectrometry: Challenges and paths forward

https://doi.org/10.2138/am-2022-8247
Trace concentrations of water in olivine strongly affect diverse mantle and magmatic processes. Accurate measurements of these low concentrations are challenging and even more so due to a ~40% disagreement between the two main studies that have produced independent water calibrations. In this study, Towbin et al. resolved the differences between these calibrations and offer recommendations for an improved ion microprobe calibration using a readily available set of standards. In light of their finding, they reevaluate published partition coefficients for water between olivine and melt. By revising the measured olivine concentrations, they improve agreement between experimentally determined partition coefficients and those determined from olivine-hosted melt inclusions.

Arsenic clustering in arsenian pyrites: A combined photoemission and theoretical modelling study

https://doi.org/10.2138/am-2022-8415
The photoemission spectra from samples of arsenian pyrite collected by Mahjoub et al. using synchrotron soft X-ray spectroscopy are compared to a series of first principles simulations of the four experimentally observed surfaces of pyrite in the presence of As atoms on the top layers that substitute for superficial S. A comparison between the spectrum of bulk As-3d in the samples with its bulk counterpart in arsenopyrite revealed a 0.6 eV shift towards lower binding energies. The calculated partial charges of atoms located at the surface of arsenian pyrite indicated that while the electron density on the As atom of As-S dimers in arsenian pyrite is less negative than the As in bulk arsenopyrite, it is more negative than the As atom of As-As dimers, which were only seen in the superficial As clusters. This firmly validated the description of As presence in arsenian pyrite as local clusters inducing localized lattice strain due to increased bond distances.

High-pressure electrical conductivity and elasticity of iron-bearing δ-AlOOH

https://doi.org/10.2138/am-2022-8393
In this contribution by Su et al., the electrical conductivity and elasticity were determined for δ-(Al,Fe)OOH with 5 and 48 mol.% FeOOH at pressures up to 75 GPa. They found that conductivity of δ-(Al,Fe)OOH may be slightly affected by high iron content and spin transition at high pressure, and concluded that subduction of Fe-bearing δ-AlOOH may account for some high conductivity regions in the lower mantle, e.g., the North Philippine Sea slab.

Nudged Elastic Band calculations of the (4H)SiX hydrogarnet type defect in Mg2SiO4 forsterite

https://doi.org/10.2138/am-2022-8449
The Nudged Elastic Band (NEB) method is used by Poe and Perna to investigate configurational transformations of the hydrogarnet defect in forsterite. Reactions involve rotational or torsional movements of OH bonds without breaking any strong chemical bonds, and activation energies do not exceed 0.6 eV. In some cases, reactions are accompanied by significant displacement of the (4H) center of mass to suggest a low-temperature means of promoting charge transport without requiring chemical dissociation of the hydrogarnet defect species.

Mn substitution and distribution in goethite and influences on photocatalytic properties from first-principles calculations and experiments

https://doi.org/10.2138/am-2022-8182
This study by Liu et al. provides one simulation frame and reveals the distribution pattern of Mn impurities in goethite, i.e., the Mn cations prefer to distribute within the cation layer approximately parallel to the (001) plane. They also predict that there may be Mn-rich nano-scale clusters or lamellae in Mn-substituted goethite even with as low Mn content as 3-4 mol% based on the phase diagram and band gap analysis. The incorporation of impurity ions can significantly decrease the band gap of goethite because of the involvement of impurity bands, here, Mn substitution enlarges the potential photocatalytic range of goethite to the whole visible and partial near-infrared light. Because visible light is the main solar radiation reaching the Earth, the enlargement of photocatalytic range provides more solar energy for photocatalyze. Doped goethite may be involved in various photochemical processes, for instance, solar-induced generation of reactive oxygen species (ROSs). ROSs can initiate subsequent degradation of organic compounds, which may be one possible reason to explain abiotic oxidation of organic compounds in desert on Earth and the absence of organics on Mars. Such photocatalytic ability probably can affect the element cycling to a non-negligible extent on both early and modern terrestrial planets.

Incorporating previously neglected oxygen associated with ferric iron into matrix corrections of microprobe data from cubic and rhombohedral Fe-Ti oxides

https://doi.org/10.2138/am-2022-8447
Dungan et al. address a long-term error in the application of 'ZAF' matrix corrections to iron-rich minerals, particularly those with high ferric iron. This mistake has prevented up to ~7 wt% oxygen from being considered as an absorbing element for Fe. Redressing this omission leads to increases in reported FeO+Fe2O3 up to 1.1 wt% for end-member Fe3O4. The routine for accomplishing this as a part of microprobe data collection is now available to users of Probe for EPMA software. Old or new data not collected with this version of the program may be recalculated with CalcZAF, an app which is available on-line.

Recycled carbonates in the mantle sources of natural kamafugites: A zinc isotope perspective

https://doi.org/10.2138/am-2022-8382
Kamafugites are extremely silica-undersaturated melts that are difficult to produce by partial melting of volatile-free peridotites, but can be experimentally yielded with CO2 being added. Nevertheless, there is still rare evidence for a CO2-rich mantle source and possible recycled carbonates in the source of natural kamafugites. Here Ma et al. take Cenozoic kamafugites from the West Qinling orogen, China, as an example to address the origin of this rare volcanic rock. Their results indicate that the West Qinling kamafugites represent the products of low-degree partial melting of a carbonated (CO2-rich) peridotite source, which provides evidence for an important role of recycled carbonates in the origin of natural kamafugite suites.

Raman analysis of octocoral carbonate ion structural disorder along a natural depth gradient, Kona coast, Hawai'i

https://doi.org/10.2138/am-2022-8406
Calcitic octocorals collected along a natural depth gradient were analyzed by Conner et al. using Raman spectroscopy to better understand the individual effects of environmental and growth rate kinetic factors on carbonate ion structural disorder. Structural disorder displayed unique trends across the environmental gradient and across varying skeletal growth rates, respectively. The results of this study have implications for Mg paleo-proxies and potentially quantifying biogenic calcite solubility using Raman.

Memorial of Charles Wilson Burnham, 1933-2021

https://doi.org/10.2138/am-2023-1016

Erratum

https://doi.org/10.2138/am-2023-E10854

Dear Colleagues,
Registration is open for the third annual Missouri S&T workshop on "Resilient Supply of Critical Minerals", funded by the National Science Foundation (NSF): https://criticalminerals.mst.edu/registration/
Please note that the deadline for travel grant applications is June 5, 2023. Information on how to apply for the travel grants (up to $1000) can be found on the workshop website:  https://criticalminerals.mst.edu/travel/travel-grants/
The workshop will be held in-person (online option available) on the Missouri S&T campus in Rolla, Missouri from August 9-10, 2023, starting at 9:00 AM U.S. Central Time.
The list of confirmed speakers can be found here:  https://criticalminerals.mst.edu/speakers/
Topical sessions will follow the most pressing research needs that were identified during the first workshops. The findings reports from the 2021https://criticalminerals.mst.edu/wp-content/uploads/sites/7/2021/10/Findings-Report_Workshop-on-Resilient-Supply-of-Critical-Minerals_Locmelis-et-al.-2021.pdf and 2022https://criticalminerals.mst.edu/wp-content/uploads/sites/7/2023/02/Summary-Report_2nd-Annual-Workshop-on-Resilient-Supply-of-Critical-Minerals-2022.pdf workshops are available on our workshop website.
[cid:image001.jpg@01D98D7A.D4B77660]
The topical sessions are:

1. The Critical Mineral Potential of the USA: Evaluation of existing and exploration for new resources.
   

2. Mineral Processing & Recycling: Maximizing critical mineral recovery from existing production streams.
   

3. Critical Mineral Policies: Toward effective and responsible governance.
   

4. Resource Sustainability: Ethical and environmentally sustainable supply of critical minerals.
   

For updates to the schedule and registration, please refer to the workshop websitehttps://criticalminerals.mst.edu/
Kind regards,
Marek Locmelis
Workshop Chair
Missouri University of Science & Technology
Geosciences and Geological and Petroleum Engineering
334 McNutt Hall, 1400 North Bishop Avenue
Rolla, Missouri, 65409-0410, USA